慢性乙型肝炎患者外周血树突状细胞诱导特异性T淋巴细胞应答

目的 探讨慢性乙型肝炎患者外周血树突状细胞(Dc)是否诱导特异性T细胞应答。方法(1)将研究对象分为慢性乙型肝炎患者组、急性乙型肝炎痊愈组、健康志愿者组,分离各组研究对象的外周血单个核细胞(PBMC),细胞内细胞因子染色方法检测其对细胞毒性T淋巴细胞(CTL)特异表位多肽乙型肝炎病毒核心抗原(HBcAg)18-27的记忆性免疫应答;(2)培养慢性乙型肝炎患者DC,将负载有乙型肝炎抗原表位多肽的DC诱导特异的T细胞应答。采用细胞内细胞因子染色方法检测诱导的T细胞分泌的细胞因子,乳酸脱氢酶释放法测定诱导的T细胞杀伤活性。结果(1)急性乙型肝炎患者PBMC对HBcAg 18-27 CTL特异表位多肽存在记忆的免疫应答,其分泌干扰素-γ的CD8+T细胞占CD8+T细胞总数的(4.3±2.5)％,分泌白细胞介素-2的占总细胞数的(4.8±2.2)％,分泌肿瘤坏死因子-α占总细胞数的(4.6±2.3)％。而慢性乙型肝炎患者和健康志愿者对其记忆应答很低,与急性乙型肝炎患者比较差异有显著性,t值为2.508-3.305,P<0.05。(2)用多肽共孵育过的慢性乙型肝炎患者DC多次诱导的T细胞慢性乙型肝炎患者组,加肽孵育的靶细胞比例为30:1、10:1、3:1时,其杀伤率分别为(57.0±20.3)％、(49.5±20.2)％、(21.8±12.9)％,均高于对照组,表明慢性乙型肝炎患者DC可以诱导特异的T

Dendritic cells originated from the peripheral blood in chronic hepatitis B patients can induce specific T cell immune response

OBJECTIVE: To study whether dendritic cells (DCs) derived from the peripheral blood in chronic hepatitis B patients can induce specific T cell immune response. METHODS: (1)The subjects were divided into 3 groups: chronic hepatitis B group (CHB), acute hepatitis B group (AHB), and normal donor group (ND). The peripheral blood mononuclear cells (PBMCs) isolated from those subjects were stimulated with HBcAg 18 to 27 CTL epitope peptide, and intracellular cytokine staining (ICCS) was used for detecting IFN-gamma, IL-2 and TNF-alpha produced by CD8+ T cell. (2) DCs generated from PBMCs were pulsed with HBcAg 18 to 27 CTL epitope peptide, then were cocultured with autologous lymphocytes for 10 days to induce antigen-specific T cell, which was assessed by ICCS and cytotoxic assay. RESULTS: (1) The memory effect of the PBMCs from AHB group to HBcAg 18 to 27 CTL epitope peptide was stronger than that from CHB or ND group (t=2.508-3.305, P<0.05). (2)After lymphocytes were cocultured with DC treated with HBcAg 18 to 27 CTL epitope peptide, antigen-specific T cell effect was induced. And the killing rates were (57.0+/-23.0)%, (49.5+/-20.2)%, (21.8+/-12.9)% at the effector/target of 30:1, 10:1, 3:1, which were higher than that in control group. CONCLUSIONS: The memory T cells against HBV antigen lacks in CHB patients. DCs from CHB patients pulsed with HBcAg 18 to 27 epitope peptide can induce HBV antigen-specific T cell, which can kill specific target cells and produce cytokines involved in virus clearance.